Dryer Vent Placement

I am moving the laundry room to the basement and need to install a dryer vent. Is it better to vent through the rim joist (wait, this house doesn't have a rim joist, the sheathing is attached directly to to the ends of the floor joists). Is it better to go through the sheathing (exterior is vinyl siding) OR should I go through the hollow concrete block below the siding?

I realize going through the sheathing is easier, but I imagine the risk of water leak is much less going through the block. In the absence of cost and money, which method is better?

Also has anyone had any experience with the Dundas Jafine BPSH4WZW ProShield 4-Inch Spring Loaded Dryer Vent Hood?

You want the discharge to be above normal snow level, so that may dictate where it goes. I'd rather cut a hole in the siding than the block. You don't want to use flexible ductwork - while harder to install, you're much better off with solid, smooth walled duct. the clothes will dry quicker and you'll have less (potentially dangerous, fire-prone) lint buildup. I've heard good things about one with a U-shaped outlet with a cap on the end. WHen the dryer is running, it pushes the cap up, it falls back when off. No springs to wear out as gravity always wins.

You want the discharge to be above normal snow level, so that may dictate where it goes. I'd rather cut a hole in the siding than the block. You don't want to use flexible ductwork - while harder to install, you're much better off with solid, smooth walled duct. the clothes will dry quicker and you'll have less (potentially dangerous, fire-prone) lint buildup. I've heard good things about one with a U-shaped outlet with a cap on the end. WHen the dryer is running, it pushes the cap up, it falls back when off. No springs to wear out as gravity always wins.